19 lo] A Structural Study of Some Caterpillars 105 



1. Labrum very shallowiy notched, all six setae near the outer edge; cervical 

 region chitinized in two pair of sclerites, which fuse more or less to the 

 corresponding sclerites of the head ; postgenae very wide. Large cones 

 with a tuft of branches (unique). Prolegs with hooks in a complete 

 circle, or shortly broken on the outer side: part of primaries modified into 

 Hat plates, the others inconspicuous. Labial setae ai close together. 



Hespcriina, Hesperiinae 



* Feet with 125 hooks, alternately of 3 lengths. Head square; 

 postgenae with setae; adfrontals abruptly widened at top of front; 

 gula as wide at base as it is long. Example: Epargyreus tityrus (Fig. 23). 



* Feet with 50 hooks, alternately of two lengths; head heart- 

 shaped ; postgenae fused with gula and without setae ; adfrontals very 

 wide and long; gula twice as wide. Example: Pholisora catullus. 



(Fig. 24). 



1. Labrum usually with setae normal (about as in Noctuidae) not all on the 



terminal margin, usually moderately notched; cervical region not 

 chitinized, postgenae meeting, or else very narrow. Large cones 

 simple, normal. Proleg with hooks never in a complete circle or horse- 

 shoe (the outer band preserved only in Jasoniades, Euphoeades) 

 primaries unmodified, usually similar to secondaries; labial setae ai 

 widely separated. Papilionina go to 2. 



2. Labrum with about 18 secondaries. Maxillary lobes very small, front 



wider than high, not reaching half way to vertex; clypeus as broad as 

 1-3 height of front, with many scattered secondaries, primaries sep- 

 arated by half the distance that separates the two primaries i from each 

 other. Lower end of adf . about as broad as clypeus. Papilionidae 



* Feet with an outer row of 45 small hooks and an inner row of 

 SO large ones. Example: Jasoniades glaucus (Figs. 11 and 22.) 



Euphoeades troilus. 



* Feet with a single row only of about 50 hooks. 



Example : Pa/iz7^'o polyxenes (Figs. 10 and 21.) 

 Laertias philenor. 



2. Labrum with less, or usually without secondaries. Maxillary lobes at least 



half as long as last joint of palpus. Front higher than wide (except 

 in Anosia) usually reaching more than half way to vertex ; clypeus 

 usually much narrower, and with less or no secondaries, when widest 

 the adfrontals are only about half as wide as it at the bottom, go to 3. 



3. Head small and body stout ; prolegs with fleshy outer lobes curving down 



over the row of hooks; clypeal setae very far apart; about as in Papilio, 



but on a narrow clypeus. Seta iv of labrum some distance from the 



margin. Adfrontals apparently very narrow. Lycaenidae 



Example: Thecla ilicis. (Fig. 38.) 



3. Head at least half diameter of body, which is approximately cylindrical ; 



■ prolegs normal ; seta iv of labrum variable. Claws of true legs deeply 

 lobed. go to 4. 



4. Primaries on body mostly distinct, in P. brassicae conspicuous; adfrontals 



very narrow ; clypeal setae far apart ; iii of labrum distant from margin 

 nearly as far as from seta ii. Pieridae 



Example: P. rapae, (Fig. 20), P. brassicae. 



4. Primaries on body not distinguishable from secondaries, at most a little 



larger; adfrontals about 1-5 as wide as height of front; clypeal setae 

 separated by a distance not more than J that between the two setae 

 i; iii of labrum close to margin. Nymphalidae 



5. Prolegs with outer hooks (4 scattered ones) ; segments of abdomen divided 



into four equal annulets, each bearing a row of larger black setae. 



Libytheinae 



Example: L. celtis. (Fig. 37.) 



5. Prolegs with the inner row of hooks only; one annulet of each segment 



broad; the larger black setae, if present, irregularly arranged, or on 



spines. go to 6. 



